In the document CIGRE, Session 1994, Aug. 28-Sep. 3, the Applicant has described in an article entitled "Introducing digital electronics in equipment auxiliaries, and improvement of reliability", by E. Thuries, G. Ebersohl, J. P. Dupraz, O. Chetay, and J. P. Moncorge, a circuit for self-monitoring and checking of a high tension circuit breaker, and the main features thereof are described below.
That circuit comprises a level zero shown in accompanying FIG. 1. It includes transducers for monitoring operating parameters of the equipment, and in particular:
for each pole of the circuit breaker, a transducer CAO indicating that the pole is in its open position; PA1 for each pole of the circuit breaker, a transducer CAF indicating that the pole is in its closed position; PA1 for each pole, a transducer SF.sub.6 delivering the pressure of the SF.sub.6 insulating gas within the pole; PA1 a transducer P indicating the oil pressure in the circuit breaker control means; and PA1 for each pole, a transducer U generating an indication enabling pole wear to be evaluated on the basis of the current passing through the pole as measured by a current transformer TI. PA1 driving in appropriate manner the open and close coils (BO, BF) without any conventional contact in the command chain, using static switches (ISO and ISF respectively); PA1 generating position information relating to the circuit breaker with a very high degree of security, by implementing an algorithm that takes advantage, in particular, of the redundancy provided by the transducers CAO and CAF, and also of any mismatch information that may arise; PA1 ensuring that all three poles reopen automatically in the event of mismatch on closing; PA1 for each operation, providing timing of two characteristic durations, namely the duration between receiving the order and leaving an initial position, and the duration between leaving the initial position and reaching the final position; PA1 ensuring the hydraulic control system is repressurized by means of a pump P and also via circuits that do not include any conventional contact, by virtue in particular of a static switch ISP; and PA1 generating signalling, alarms, and interlocks for any observed failure during self-testing controlled by the circuit SMP, whether applicable to the transducers or to the hydraulic control circuits. PA1 periodic self-testing of the position transducers, determining the positions of the poles while in the standby state and while being driven; PA1 applying appropriate commands to the coils BF and BO via the static switches ISF and ISO on the basis of orders acquired in the remote terminal microcontroller MBD; PA1 continuous self-monitoring of the command circuits, including the static switches ISF and ISO; PA1 timing the operating durations of the poles while they are being driven; and PA1 recording all of the above information in the distributed database. PA1 acquisition, from Level 1, of open and close orders and recording of said information in the database, and consequently forwarding it to the stations; PA1 determining the position of the circuit breaker on the basis of the information produced by the microcontrollers associated with each of the phases (S1, S2, and S3); PA1 responding automatically to pole position mismatch; PA1 generating and issuing alarms whenever failures are observed, whether during self-testing or because the poles are in abnormal positions; and PA1 generating an alarm indicating failure of a station or of the local network. PA1 the maximum duration of an opening or of a closing operation for each pole; PA1 the average speeds of the primary contacts; PA1 possible lack of synchronization between the poles; and PA1 keeping a count of the operations performed by each pole.
The data from all the above transducers is applied to a multiprocessor system SMP constituting a local distributed database; the system SMP also receives orders to open and close the circuit breaker from controllers and protective equipment situated in level 1, and represented in the figure by rectangle PRA.
The system SMP talks with the stage PRA via a microcontroller MBD referred to as a remote terminal microcontroller since it is located remotely from the circuit breaker being monitored. The microcontroller MBD constitutes a database which is a replica of the database in the system SMP.
The link between the microcontroller MBD and the system SMP is provided over optical fiber links that are not sensitive to electromagnetic disturbances.
The stage PRA may be connected to the microcontroller MBD in various different ways depending on whether the monitoring/control architecture of the station is conventional or digital. If conventional, parallel links (preferably via optical fibers) serve to transmit orders for opening and closing O/C, signalling SIG, and database access ABD.
If digital, the same interchanges are possible either via a two-way serial optical link or else, and preferably, by direct access to the dual-input memory that contains the database.
The function of the circuit SMP is as follows:
FIG. 2 is a block diagram of the multiprocessor system SMP.
The system is made up of a plurality of microcontrollers each constituting a respective database that serves not only to provide respective applications software but also software for communication with a local network RL that enables the distributed database to be managed and periodically refreshed, and that serves, in particular, to ensure that the same data is recorded simultaneously in each of the distributed databases. One such local network is described in document FR-A-92/06921.
Three microcontrollers S1, S2, S3 (stations No. 1, 2, and 3) associated with the position sensors CAO and CAF for each of the three phases A, B, and C of the circuit breaker perform the following functions:
The microcontroller MaD (station No. 0, interface) has the following main functions:
A microcontroller S7 (station No. 7) deals with mechanical monitoring and makes use of the time-related data generated by the microcontrollers S1 to S3. This data is accessible in the database and makes it possible to monitor the following:
Operating anomalies are encoded and stored for subsequent analysis of the behavior of the circuit breaker.
Two microcontrollers S5 and S6 (stations No. 5 and No. 6) serve respectively, for each pole, to monitor the electrical wear of its contacts and the density of its insulating SF.sub.6 gas.
For this purpose, station No. 5 receives data in its database relating to open and close orders; in response, this station provides "electrical wear" data.
Station No. 6 enriches the distributed database with SF.sub.6 data relating to each pole. The stations S1 and S2 thus have access to the information concerning them and they can adopt an appropriate corresponding strategy on receiving an order.
Microcontroller GR manages the local network RL by specifying within the frames thereof which stations are consuming and/or producing such and such a data item, and it does this at the rate with which each data item in the distributed database is periodically refreshed.
A special card TB referred to as the "bus translator" translates between a wire bus and an optical bus BO. For reasons of electromagnetic compatibility, the copper wire bus is thus rigorously confined within an electronics rack, while optical links are used whenever it is necessary to avoid pick-up of external disturbances.
A microcontroller S4 (station No. 4) provides a software bridge between the network RL and a serial link LS going to the Level 1 microcomputer which is preferably of the PC (personal computer) type and which is referred to below by the letters PC.
For maintenance purposes, this link makes it possible to establish a man-machine interface for the purpose of reading the information contained in the distributed database.